The clutches of an automatic transmission may be selectively engaged to execute a clutch-to-clutch power upshift to a higher gear state. A controller is used to synchronize clutch speeds, and to thereafter coordinate the transfer of torque within the transmission. The controller ensures that the particular clutch associated with the current speed ratio (the off-going clutch) smoothly releases while the clutch associated with a desired new speed ratio (the on-coming clutch) smoothly engages. In order to effectively control the shift event, the controller must be aware of the clutch pressure/clutch torque relationship for the oncoming clutch.